This application relates to a gas turbine engine component wherein a plurality of cooling channels extend radially outwardly through an airfoil, and have crossover holes to supply impingement cooling air to both the suction and pressure walls of the airfoil.
Gas turbine engines are known, and typically include plural sections. Often a fan delivers to a compressor section. Air is compressed in a compressor section and delivered downstream to a combustor section. The compressed air is mixed with fuel and combusted in a combustor section. Products of combustion then pass downstream over turbine rotors. The turbine rotors typically receive a plurality of removable blades. The products of combustion are quite hot, and the turbine blades are subjected to high temperatures. In addition, stationary vanes are positioned adjacent to the rotor blades.
To cool the blades and vanes, cooling schemes have been developed. Air may be circulated within various cooling channels in an airfoil that defines part of the blade or vane. In many known airfoils, the cooling air flows along radial paths. Alternatively, the cooling air may flow through serpentine paths within the blade to cool the blade. With either of these schemes, cooling is more efficient near a root of the airfoil, before the air is unduly heated. Also, such paths may need to taper, as air is bled off through film cooling holes. This also results in less cooling near a tip of the airfoil.
Impingement cooling air channels have been provided adjacent a trailing edge or a leading edge of the blade. In this type channel, cooling air is received from a core and directed against an outer wall of the blade. Impingement cooling channels have generally not been used along the sides of the airfoils.
Recently, a type of cooling channel known as a “micro-circuit” has been developed. A “micro-circuit” is a very thin cooling channel formed adjacent a suction or pressure wall of the turbine blade. These channels receive cooling air from radial flow channels and perform some cooling on the suction or pressure wall. Typically, air passes through a torturous path over pedestals.
Impingement channels are simpler to manufacture than microcircuits or serpentine paths. Even so, impingement cooling has not been relied upon as essentially the exclusive mode of cooling an airfoil in the prior art.